I heard it's a community thing where people on JP servers don't go on pf (or is it DF?) until they know the fight, so it's the norm for each player to have done their homework before they queue in. So players go in, execute the community standard strategy and then get the clear in short order.
The previous, unsure if still true in Shadowbringers, trend for JP has been they PF for the sake of practice and then being able to execute it in DF so you're right there. So this is where you end up with a more consistent strat base, better use of macros, and just generally a more willingness to simply "do as told" rather than people doing whatever split tanks/healers/DPS wise for positioning.
It's always funny when you PF something and someone only knows the fight from a specific position; literally no mechanics change but E instead of W or E instead of SE and suddenly they're griping.
Then there are people who try to sneak into clear parties when they clearly don't know squat, hoping to get carried to a clear. It's very inconsiderate.
There's a lot to be said about many people's suggestions are to practice in PF the phase ahead of where you are, the general trend of people assuming others are at fault, not pulling their own weight but thirsty for clears, etc. Hell, you can see it a lot with statics too where they limp into seeing X phase and it's suddenly "PHASE PROG NOW." Watching a lot of TEA prog and seeing people limp into BJ/CC or Wormhole or Exatrine and it quickly becomes Phase 2 / Wormhole / Clear prog despite another 20-30 pulls of previous phase prog to clean up to even get there again.
I pretty much only ever do any content with my static so most my observations are basically just the reactions here and on reddit so my take is mostly not really my take, I guess? So take it all with a grain of salt.